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Fuel delivery issues on my '63 (401 no a/c)


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 Here's the saga so far. I had my 4GC carb rebuilt by a known to be good and recommended shop in San Diego. Initial issues were flooding due to stuck or out of adjustment floats. After rebuild and installation, the Riv bogs down on any longer or steeper inclines, and bogs down at anything above 50 mph, so freeway driving is out of the question. No bog from standstill.

I took it back (installed on the car) to the shop. They checked:

  - The float adjustment, all vacuum hoses,and inlets, accel pump function, and secondaries function.

   - All rubber and metal fuel lines back to the fuel tank for kinks or crimps. 

   -To see if the tank sock was clogged by blowing compressed air into the fuel line from the inlet side of the fuel pump and listening/looking at the tank fill tube with gas cap off. All good,

   - Scoped the ignition system (has a Pertronix Ignitor). All OK.

   - The fuel pump, which was putting out about 6+ lbs. pressure, but IIRC that was at idle or low revs while in Park.

 The chief mechanic is out of ideas but said the fuel pump could be failing under load. Other ideas welcome as to what else may cause fuel starvation on steeper inclines as well as limiting the speed to under 50. I may have to inspect the fuel tank more closely, but for now, can someone recommend where to get a decent quality fuel pump these days? The shop recommended NAPA but maybe my fellow ROA members have another recommendation?

  Again, any other ideas of what to check for are welcome - maybe some of you have had a similar issue.

P.S. I did manage to to get my Riv there and back home under its own power, but it was a real challenge at times because of the canyon topography in this area!

 

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1 minute ago, JanZverina said:

 Here's the saga so far. I had my 4GC carb rebuilt by a known to be good and recommended shop in San Diego. Initial issues were flooding due to stuck or out of adjustment floats. After rebuild and installation, the Riv bogs down on any longer or steeper inclines, and bogs down at anything above 50 mph, so freeway driving is out of the question. No bog from standstill.

I took it back (installed on the car) to the shop. They checked:

  - The float adjustment, all vacuum hoses,and inlets, accel pump function, and secondaries function.

   - All rubber and metal fuel lines back to the fuel tank for kinks or crimps. 

   -To see if the tank sock was clogged by blowing compressed air into the fuel line from the inlet side of the fuel pump and listening/looking at the tank fill tube with gas cap off. All good,

   - Scoped the ignition system (has a Pertronix Ignitor). All OK.

   - The fuel pump, which was putting out about 6+ lbs. pressure, but IIRC that was at idle or low revs while in Park.

 The chief mechanic is out of ideas but said the fuel pump could be failing under load. Other ideas welcome as to what else may cause fuel starvation on steeper inclines as well as limiting the speed to under 50. I may have to inspect the fuel tank more closely, but for now, can someone recommend where to get a decent quality fuel pump these days? The shop recommended NAPA but maybe my fellow ROA members have another recommendation?

  Again, any other ideas of what to check for are welcome - maybe some of you have had a similar issue.

P.S. I did manage to to get my Riv there and back home under its own power, but it was a real challenge at times because of the canyon topography in this area!

 

 

 

That sounds exactly like the symptoms when my fuel pump went on my 63. I replaced it with a NAPA fuel pump and have not had any issues. That was 5 years ago. I also had a significant increase in fuel mileage. With the old fuel pump I was getting 9-10 mpg. Now I get 13-16 mpg. 

 

Bill

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Put a fuel pump on the car! Also check for any cracks in the  suction fuel line from the tank to the pump. By the way, the way you are checking the

sock in the tank sounds bogus to me. I would go ahead and put on a new one if the fuel pump doesn't solve it. Also, a low float level on the carb would do

what your car is doing......are you certain the float level is correct?

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Thanks Bill and Winston. Winston - you recommend NAPA as well? Yes, float levels were already checked twice. I can also eliminate the fuel tank and lines altogether by running a 5-gallon can and hose straight into the pump.

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Correct float levels on the 4GC are imperative. They are diff. front & rear.  BEFORE replacing fuel pump check the outlet hose at the tank. It curves up & it good have a crack in it that sucks air under even a light demand & will NOT leak fuel.  For the heck of it replace it especially if original & road test.  It doesn't have A/C so you can't block the return line as no A/C has no return line.

Report back

 

Tom T.

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Anyone know the difference between the fuel sending units (tank-mounted) for '63 and '64? CARS Inc. lists '64 only and they're unsure. Does anyone know if the sock is the same? I'm more interested in obtaining a new sock for a '63 tank, non-A/C if that matters. More diagnosis to come this weekend, the first inspection being the hose outlet at the tank as tel riv suggests.

Thanks!

 

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Somewhere between 1963 and 1965 the ohms changed from 45 to 90.  I thought it was in 1965 but I'm not positive.  Someone is though.  That could be it.  Does CARS offer one for a 65?

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Jan,

 

   Fuel sending units were 45ohms '64 & back. 1965 & up were 90ohms.  The fuel socks are all the same & are still available from GM & are 3/8ths.

On the Skylarks the diff. is they are 5/16ths. & 3/8ths for Skylark GS. Bigger engine more fuel required to feed it.

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1 hour ago, JanZverina said:

Thanks TelRiv, 

Do you have a part #? The Genuine GM parts website does not let me go earlier than 1984. Much appreciated!

 

Ordered the AC Delco TS 1000 from Rock Auto for my car. Available from many different sources and is inexpensive. A smidge too small for the inlet. My shop had no problems enlarging the inlet.

 

Bill

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Bill, 

The TS 1000 is what I put on my 64 and we had to enlarge the inlet a tad to get it to fit as well.  I'm wonder if the part # I posted might fit w/o having to modify it.  Both parts look the same. Perhaps it might be just the difference in the inlet size.  Perhaps we can talk Jan into buying one of each and comparing them for everyone and posterity.

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Many thanks Ed, I'll order the sock.

Hi TelRiv,

Per your suggestion I removed and inspected the short outlet hose at the leading edge of the gas tank. It didn't have any obvious cracks and held under air pressure, but I replaced it because it may have been there for 56 years, and that tank side clamp is tricky to get to. I was able to drop the front of the tank just enough to get the needed access. Ran out of time this weekend, but I have a fuel pump coming mid-week.   

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From Rivnut:

I Googled 'ACDelco fuel tank 3/8" sock' and found this:  ACDelco 5651711 GM Original Equipement Fuel Pump Strainer.  About $12

SENDING UNIT FILTER SCREEN-3/8"  

 

I'm finding that the GM 5651711 fuel sock as well as the TS 1000 recommended further up in this thread at no longer available. Can anyone suggest an alternative?

Thanks!

 

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58 minutes ago, JanZverina said:

From Rivnut:

I Googled 'ACDelco fuel tank 3/8" sock' and found this:  ACDelco 5651711 GM Original Equipement Fuel Pump Strainer.  About $12

SENDING UNIT FILTER SCREEN-3/8"  

 

I'm finding that the GM 5651711 fuel sock as well as the TS 1000 recommended further up in this thread at no longer available. Can anyone suggest an alternative?

Thanks!

 

There is a TS1000 on e-bay right now.

 

Bill

Edited by Riviera63 (see edit history)
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Jan,

 

   No use just one.  Use some weather strip adhesive to glue the gasket to the pump.  Put some grease on the arm that contacts the eccentric. Make sure the pump arm is UNDER, NOT on top of the eccentric.  To kinda make the job easier get the engine at TDC #1 & the eccentric should be up making the pump easier to install

 

Tom T.

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Hi all,

A weekend update, as they say:

Step I: I replaced the fuel pump with a Delphi one from Rock Auto, hopefully not crap. NAPA says the pump is NLA. Since they don't cost much I also ordered one from CARS Inc. which looks to be identical except for no casting of the Delphi name on the pump housing. Prior to installation I rotated the engine to line up the balancer notch at zero, with the rotor pointed toward Cyl. No. 1. The old fuel pump came out easy and the new one went in w/o any struggle. The Riv fired right up, ran on the choke for 30-45 sec or so, and then would stall.

Step 2: Changed the gas filter just to be sure, with the 'IN' or dimples on the inlet side (from the fuel). No difference. I'm definitely getting gas via the pump into the carb (a 4GC.) 

Step 3: I filled my 5-gallon container with fresh fuel, purchased several feet of the best fuel hose (yes, it is expensive per foot!) and ran it from the container into the fuel pump inlet, bypassing any possible fuel tank issues such as a bad sock or other cloggage. I already changed the short hose at the tank and the hose by the right front coil spring. Even with the car's fuel tank connected I'm getting plenty of fuel into the carb visa the pump. 

  So I'm running out of ideas and am back to suspecting the float adjustment or another carb issue.

This may be a clue or not, but worth a mention: This all started a month or so ago after I had the 4GC rebuilt by a recommended carb shop here in San Diego (about the only one left) using a rebuild kit from the Carburetor Shop in Eldon, Missouri. Upon reinstallation it was getting no fuel at all, so rebuilder checked acccel pump and then removed the tiny springs that as I understand it are under the floats on a 4GC. He said the carb was "over engineered" in that area and he typically doesn't reuse them. Upon reinstallation the Riv fired right up and ran well - until encountering any inclines or speeds over 45 mph. The it starts bogging down or stalling, not ideal for San Diego freeways and canyon roads!

So any suggestions on where to look next are much appreciated.

Some questions:

- Does anyone know a good rebuilder (anywhere) to whom I could send the carb to for a thorough diagnosis? I'm done with taking it back to this shop.

- Does anyone have a running 4GC they'd like to part with? I'm leery of buying someone else's problem on eBay, etc.

- Am I better off with a Carter AFB or later Quadrajet, and does that mean another manifold or different linkages, etc.?

- What have others done as far as their carb set-up on a '63 Riv that may not be completely stock but makes the car functional and more reliable?

  Many thanks for your time!!!

 

   

 

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Jan,

 

   Since you are still having problems the next thing I would do, as I feel you just about covered everything else, is install the points back into your distributor.   I as well as MANY others have had all kinds of different problems with Pertronix conversions.  Remove the Pertronix & re-install points

& condenser & adjust the dwell & check ignition timing.  Something simple to do & shouldn't take you more than 1/2-1 hour.

At this point it's worth a shot.

Just my opinion.

 

Tom T.

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Jan,

 

   I don't think so, BUT if you have the old one sitting around it for sure wouldn't hurt to try.

 

Maybe do some research on the subject to find out for sure, but I don't feel/think there would be a problem.

 

Tom T.

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Sounds like the prime suspect remains the carb.  

 

But, it may be helpful to attach a mechanics grade vacuum gauge

on a long hose and have it in the cockpit while replicating the symptoms you’ve described.

Ported and non-ported vacuum should be checked as part of the vacuum exercise; incl. vacuum advance function.

Bet this is in the Riviera shop manual....?

Vacuum advance mechanisms can bind and cause the bogging you describe at higher rpms and load.

Im assuming your rebuilder/mechanic would have done so.....?

 

Ive had a love /hate relationship with 4GCs for YEARs!  For ex., I Learned many years ago about the many variations for accelerator pumps on Buicks.  Stir in the advent of neoprene pump skirts (one size fits all 🤣...... not on Buicks) instead of the correct Rochester 

leather cups and you got problems.   

 

I finally reluctantly bagged my 4GCs and replaced with model correct Carter AFB on my 58 Roadmaster.  Trouble free for 30 years after that.

You may want to acquire one that is correct or close to correct for your 401..... and try it.

 

The following is an editorial comment:

 

Im to the point that my next Buick project will be a Holley Sniper Fuel injection system that fits under the stock air cleaner and integrates the MSD ignition control with their billet distributor.  I love the old stuff.........but, parts quality,availability, and expertise is becoming a limiting factor in enjoying the old cars....... In the end I just wanna drive the wheels off ‘em and not get caught out by

failing points,condensers, carb parts, coils, etc. etc.

 

my 2 cents😜

 

 

 

 

 

 

 

 

 

 

 

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I hadn't previously commented on this thread, as the OP stated he had a pertronix conversion, and generally pretty much a waste of time trying to fix a "carburetor problem" when there is an electronic whizback of questionable quality firing the gas.

 

Since another poster has suggested upgrading the ignition to the original points, I will throw in my two cents as well. 

 

The 4GC carburetor has several circuits. If the engine runs well at 45 MPH it is running on the main metering circuit(as opposed to idle). Other than load (a hill, or rapid acceleration), the main circuit is good up to almost maximum RPM. In other words, if the carb is OK at 45 MPH, it should also be good at 100 MPG (but accelerating slowly to get there). The car should run 100 MPH on the main circuit without the use of the power circuit.

 

I don't know what is the problem, but don't think it is the carburetor.

 

Possibles:

 

(1) ignition

(2) fuel delivery system (fuel pump)

(3) ignition

(4) fuel delivery system (small leak in fuel line, not enough to see, but sucking air and restricting fuel flow)

(5) ignition

(6) fuel delivery system (non-functioning fuel tank vent)

(7) ignition

(8) fuel filter

(9) did I mention ignition? ;)

 

Suggestion: if upgrading to a real ignition doesn't solve the issue, try borrowing a marine fuel tank for an outboard, and an electric fuel pump and connect directly to the carburetor. This would bypass any fuel delivery system issue. Once you have determined the culprit is either the ignition or the fuel delivery system, then easier to fix.

 

Jon.

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24 minutes ago, carbking said:

I hadn't previously commented on this thread, as the OP stated he had a pertronix conversion, and generally pretty much a waste of time trying to fix a "carburetor problem" when there is an electronic whizback of questionable quality firing the gas.

 

Since another poster has suggested upgrading the ignition to the original points, I will throw in my two cents as well. 

 

The 4GC carburetor has several circuits. If the engine runs well at 45 MPH it is running on the main metering circuit(as opposed to idle). Other than load (a hill, or rapid acceleration), the main circuit is good up to almost maximum RPM. In other words, if the carb is OK at 45 MPH, it should also be good at 100 MPG (but accelerating slowly to get there). The car should run 100 MPH on the main circuit without the use of the power circuit.

 

I don't know what is the problem, but don't think it is the carburetor.

 

Possibles:

 

(1) ignition

(2) fuel delivery system (fuel pump)

(3) ignition

(4) fuel delivery system (small leak in fuel line, not enough to see, but sucking air and restricting fuel flow)

(5) ignition

(6) fuel delivery system (non-functioning fuel tank vent)

(7) ignition

(8) fuel filter

(9) did I mention ignition? ;)

 

Suggestion: if upgrading to a real ignition doesn't solve the issue, try borrowing a marine fuel tank for an outboard, and an electric fuel pump and connect directly to the carburetor. This would bypass any fuel delivery system issue. Once you have determined the culprit is either the ignition or the fuel delivery system, then easier to fix.

 

Jon.

"Electronic whizback"....I like that....

Tom

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CarbKing brings up a good point on Pertronix............

Never used their stuff , so I’m NOT a hater, but,

Having spent a bunch of time at the Cadillac forums as well.......... a lot of 

stories over there that take a dim view of the reliability..... even many of the advocates are carrying a set of points

in the glove box to avoid the hook.

 

Cant wait to hear about the progress on this problem...... the older I get the more perverse pleasure I get from trying 

to shoot trouble thru an iPad.....!

 

 

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Latest update for those still following along:

  After eliminating any (or at least most) fuel tank and line issues by running a fuel hose from a 5-gallon container to the fuel pump inlet and still getting the same symptoms, I broke out my AAA Plus card yesterday and had the Riv flat-bedded to another shop that specializes in vintage car repair and is known for its electrical diagnostics. After a half-day of diagnostics, they concluded that the carb is still the culprit. Ignition system (including Pertronix), advance/timing, fuel pump and filter (both new), etc. all tested fine. He sourced another 4GC from a carb builder in LA who engine-tests all his carbs. The other option was getting an Edelbrock and then having to fabricate the linkages and get the massive Riviera air filter housing to fit properly.

   More news mid-next week. If it turns out that it was the first carb being rebuilt improperly or the rebuilder not noticing anything amiss or defective with the castings, I guess I have some options - the first one being a conversation with him regarding at least a partial refund. I've been back to him twice already - the first time when the carb was not getting any fuel whatsoever, and the second visit when I drove the car to his shop under hazardous conditions because of a 40 mph limit and uphill sputtering, and 5 1/2 hours later he was still insisting it wasn't in the carb. 

  Thanks again to all who have offered suggestions, procedures, and encouragement!        

 

P.S. I think I asked but I can't recall if I received an answer: On a '63 Riv, does the Carter AFB require a different intake manifold and linkage setup than the 4GC?

 

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Eons ago the 4GC on my 63 was in need of a rebuild. At that time 1st generation Rivieras were still used cars and could be found in most salvage yards.  I pulled a Carter AFB from a 63 Riviera and put a cheap kit in it.  I got it from the owner as a "loaner" with the provision that I'd put the kit in the AFB, use it while I had the 4GC professionally rebuilt, and swap them back once the 4GC was rebuilt.  I liked the way the AFB ran and took my time getting the 4GC to a rebuilder.  About a month later I drove by the yard and there was a notice  from the Sheriff's office that the yard was closed.  Another couple of months later I found out the owner of the yard was wearing an orange jump suit somewhere up the river.  No way to return the AFB.  It's still on the car.  I sold the Rochester.  To bring this to conclusion, the 4GC to AFB was a simple r&r.  Everything bolted up with no modifications or adjustments. A simple plug and play.

Edited by RivNut (see edit history)
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14 hours ago, JanZverina said:

 

   More news mid-next week. If it turns out that it was the first carb being rebuilt improperly or the rebuilder not noticing anything amiss or defective with the castings, I guess I have some options - the first one being a conversation with him regarding at least a partial refund. I've been back to him twice already - the first time when the carb was not getting any fuel whatsoever, and the second visit when I drove the car to his shop under hazardous conditions because of a 40 mph limit and uphill sputtering, and 5 1/2 hours later he was still insisting it wasn't in the carb. 

  Thanks again to all who have offered suggestions, procedures, and encouragement!        

 

 

 

Obviously, I was wrong about the carb. Glad you found the issue.

 

Jon

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Thanks Jon and Ed. Good to know it's a direct replacement.

I'm waiting on the 4GC but I still would like to eventually find an appropriate Carter AFB for my '63 without fear of inheriting someone else's potential issues. Is there a tin tag # or casting # that denotes a '63 or are they generally all the same from 19xx to 19xx on the Riv or a slightly earlier model?

Thanks again. I'll keep everyone updated on any progress later this week.

 

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Check Jon's website, www.thecarburetorshop.com, and you can find the correct AFB carb number in the list.  Look for kits for Buicks by year.  Then by model (Riviera) number. 1963 is 4700. Then by cubic inches.  Or, look in your chassis manual.

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  Latest update: The carb shop in LA let us know that the 4GC he had for rebuild failed the on-engine tests and he's still looking into why. So my mechanic suggested we try an Edelbrock 1406 w/ electric choke and now the Riv is running strong and smooth. Picked it up today - drove it on coastal roads and freeway and no issues at all. So... as mentioned I have to have a conversation with the shop that "rebuilt" my 4GC to see if we can come to some agreement on a refund or partial refund. Any suggestions on what's fair? I know some of you are in the repair business and time is $$, but I paid ~$450 plus to get a well-performing carb and that was not the case.

  BTW we used a small adapter so I could retain the original large red air cleaner housing. I always thought its air intake pointed toward the power steering pump but page 3-7 of the factory Chassis Manual is not exactly clear. It says "standard" 4 bbl air cleaners should have the air inlet tube positioned about 15 degrees to the right of the center line of the engine. I take that to mean passenger side.  The text does mention "except Riviera engines" but it's not very clear.

  Thanks, glad to be nearing the end of this project.      

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